Notifying contacts whenever you change your number for some odd reason becomes such a difficult task that WhatsApp has addressed.
While the feature was already rumored on Android and iOS, it is now coming to the Windows Phone as well.
As with all beta launches, the developers have introduced the new feature in the beta channel. People tend to change their contact numbers and when they do, there are so many groups and friends to be notified off. After all, no one wants to suddenly lose contact with their social circle. There are plenty of situations where one has to change their phone number, be it to get better plans, moving out of country or maybe to avoid some annoying contacts. Whatever the reason is, now you can be rest assured that WhatsApp will take care of it for you.
In the screenshot of the beta version on Windows Phone, it shows three different choices to pick from. The screen suggests that people will be notified with your old number and the new number that you have changed to. Privacy has always been a huge concern when it comes to sharing phone numbers. No user would want to share their changes to everyone just because they are in their contact. The team has identified the problem by allowing you to choose to share your number with all the contacts on your phone or only with those whom you have regularly chatting.
It is obvious that if you are going to have a regular chat with some of the contacts, they are possibly your friends or office colleagues. In case, there are some unknown or unwanted members in the chat list you can just remove them all before sending out a message that lets everyone know your new number. Another option is very simple, you can just say no to all of them and manually share your numbers later. WhatsApp will not do anything on your behalf so as to let you stay anonymous if you like to. The screenshot also confirms that it will send a notification to all groups by default. It is to be clarified whether it can be disabled because obviously sharing numbers in groups may once again expose your phone number to people you are not friends with.
The feature is disabled by default and works only on the beta version of WhatsApp. You have to install the beta version after uninstalling the original version to get this feature before everyone else or you can just wait!